arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.02477cs.CVcs.CL

理解多模态大语言模型中的对齐:一项综合研究

Understanding Alignment in Multimodal LLMs: A Comprehensive Study

Apple Inc.(苹果公司)

Elmira Amirloo, Jean-Philippe Fauconnier, Christoph Roesmann, Christian Kerl, Rinu Boney, Yusu Qian, Zirui Wang, Afshin Dehghan, Yinfei Yang, Zhe Gan, Peter Grasch

AI总结:

本文系统研究多模态大语言模型的偏好对齐,比较离线与在线算法及偏好数据集构建,并提出无需额外标注或外部模型的 BDHS 数据生成方法,在多项基准上取得有竞争力的对齐效果。

摘要:

偏好对齐已成为提升大语言模型(LLM)性能的关键组成部分,但其在多模态大语言模型(MLLM)中的影响仍相对缺乏充分探索。与语言模型类似,用于图像理解任务的 MLLM 会遇到幻觉等挑战。在 MLLM 中,幻觉不仅可能表现为陈述错误事实,还可能表现为生成与图像内容不一致的回答。MLLM 对齐的一个主要目标,是促使这些模型让回答更紧密地与图像信息保持一致。近来,多项工作引入了面向 MLLM 的偏好数据集,并考察了不同的对齐方法,包括直接偏好优化(DPO)和近端策略优化(PPO)。然而,由于数据集、基础模型类型和对齐方法存在差异,目前仍不清楚哪些具体因素对这些工作所报告的提升贡献最大。本文中,我们独立分析 MLLM 中偏好对齐的各个方面。我们首先将对齐算法分为两类:离线方法(如 DPO)和在线方法(如 online-DPO),并表明结合离线与在线方法在某些场景下能够提升模型性能。我们回顾了多种已发表的多模态偏好数据集,并讨论其构建细节如何影响模型性能。基于这些洞见,我们提出一种称为偏差驱动幻觉采样(BDHS)的新型多模态偏好数据创建方式,该方法既不需要额外标注,也不需要外部模型;同时表明,在一系列基准上,它能够取得与此前已发表的多模态模型对齐工作相比具有竞争力的性能。

英文摘要:

Preference alignment has become a crucial component in enhancing the performance of Large Language Models (LLMs), yet its impact in Multimodal Large Language Models (MLLMs) remains comparatively underexplored. Similar to language models, MLLMs for image understanding tasks encounter challenges like hallucination. In MLLMs, hallucination can occur not only by stating incorrect facts but also by producing responses that are inconsistent with the image content. A primary objective of alignment for MLLMs is to encourage these models to align responses more closely with image information. Recently, multiple works have introduced preference datasets for MLLMs and examined different alignment methods, including Direct Preference Optimization (DPO) and Proximal Policy Optimization (PPO). However, due to variations in datasets, base model types, and alignment methods, it remains unclear which specific elements contribute most significantly to the reported improvements in these works. In this paper, we independently analyze each aspect of preference alignment in MLLMs. We start by categorizing the alignment algorithms into two groups, offline (such as DPO), and online (such as online-DPO), and show that combining offline and online methods can improve the performance of the model in certain scenarios. We review a variety of published multimodal preference datasets and discuss how the details of their construction impact model performance. Based on these insights, we introduce a novel way of creating multimodal preference data called Bias-Driven Hallucination Sampling (BDHS) that needs neither additional annotation nor external models, and show that it can achieve competitive performance to previously published alignment work for multimodal models across a range of benchmarks.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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